Engineering Commons^™

Development Of A Novel Bioprinting System:Bioprinter, Bioink, Characterizationand Optimization, Chandler Alan Warr

Theses and Dissertations

The use of 3D printing in biological applications is a new field of study given that 3D printing technology has become more available and user friendly. Possible uses include using existing 3D printing polymers to use in extracorporeal or in vitro devices, like Lab-on-a-Chip, and the development of new biologically derived materials to print cell-containing constructs. The latter concept is what is more commonly known as bioprinting. Our research had the goal of developing a bioprinting system including the printer, a bioink, and a feedback system for printing parameter optimization which could be done cheaply and within the reach of …

An Atomistic Approach For The Survey Of Dislocation-Grain Boundary Interactions In Fcc Nickel, Devin William Adams

Theses and Dissertations

It is well known that grain boundaries (GBs) have a strong influence on mechanical properties of polycrystalline materials. Not as well-known is how different GBs interact with dislocations to influence dislocation movement. This work presents a molecular dynamics study of 33 different FCC Ni bicrystals subjected to mechanical loading to induce incident dislocation-GB interactions. The resulting simulations are analyzed to determine properties of the interaction that affect the likelihood of transmission of the dislocation through the GB in an effort to better inform mesoscale models of dislocation movement within polycrystals. It is found that the ability to predict the slip …

Robust Coil Combination For Bssfp Mri And The Ordering Problem For Compressed Sensing, Nicholas Brian Mckibben

Theses and Dissertations

Balanced steady-state free precession (bSSFP) is a fast, SNR-efficient magnetic resonance (MR) imaging sequence suffering from dark banding artifacts due to its off-resonance dependence. These banding artifacts are difficult to mitigate at high field strengths and in the presence of metallic implants. Recent developments in parametric modelling of bSSFP have led to advances in banding removal and parameter estimation using multiple phase-cycled bSSFP. With increasing number of coils in receivers, more storage and processing is required. Coil combination is used to reduce dimensionality of these datasets which otherwise might be prohibitively large or computationally intractable for clinical applications. However, our …

Techniques For Using Internal Strain-Energy Storage And Release Inorigami-Based Mechanical Systems, Mary Elizabeth Wilson

Theses and Dissertations

The objective of this thesis is to develop and demonstrate techniques for self-deployment of origami-based mechanical systems achieved through internal strain-energy storage and release, with special application to medical implant devices. The potential of compliant mechanisms and related origami-based mechanical systems to store strain-energy make them ideal candidates forapplications requiring an actuation or deployment process, such as space system arrays and minimally invasive surgical devices. The objective of this thesis is achieved by first categorizing differentdeployment methods in origami-based, deployable mechanisms and then further exploring the use of strain energy to facilitate actuation in deployable mechanisms. With this understanding inplace, …

Implementation And Analysis Of The Iso/Iec/Ieee P21451-1 Draft Standard For A Smart Transducer Interface Common Network Services And Its Applications In The Internet Of Things, Russell Henry Albert Trafford

Theses and Dissertations

The Internet of Things (IoT) has rapidly become the paradigm for the creation and improvement of new and old Cyber Physical Systems (CPS), but how much longer can this development of IoT devices, networks, and services be sustained? The past decade has seen incredible growth in internet connected devices, with current estimates placing the number of such devices at about 20 billion in 2017, not including personal computers, smart phones, and tablets. This has created a massive market for these devices, with each company making their own applications, protocols, and services. Since these markets are competitive, there originally was no …

Emotion Recognition Using Facial Feature Extraction, Demiyan Smirnov

Theses and Dissertations

Computerized emotion recognition systems can be powerful tools to help solve problems in a wide range of fields including education, healthcare, and marketing. Existing systems use digital images or live video to track facial expressions on a person's face and deduce that person's emotional state. The research presented in this thesis explores combinations of several facial feature extraction techniques with different classifier algorithms. Namely, the feature extraction techniques used in this research were Discrete Cosine/Sine Transforms, Fast Walsh-Hadamard Transform, Principle Component Analysis, and a novel method called XPoint. Features were extracted from both global (using the entire facial image) and …

Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel

Theses and Dissertations

In this paper, polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and zinc oxide (ZnO) were combined to create functionalized piezoresistive and piezoelectric sensors for pressure sensing and energy harvesting. Samples were foamed to show that the increased deformability of the foam sensors makes them suitable for a range of applications including dexterous robotics, tactile sensing, energy harvesting, and biosensing. Uniform dispersion of CNTs was achieved with chloroform as the solvent. Samples were foamed using chemical blowing and scaffolding but granulated sugar at 70% porosity resulted in foamed samples with the most consistent mechanical properties. Samples underwent tensile and compressive testing for their …

Evaluation Of The Cracking Performance Of Geogrid-Reinforced Hot-Mix Asphalt For Airfield Applications, Daniel Offenbacker

Theses and Dissertations

The objective of this study was to evaluate the fatigue cracking performance of geogrid-reinforced Hot-Mix Asphalt (HMA) for use in airfield runways. An airfield HMA mixture with four different geogrid types were selected for this study. The geogrids varied in tensile strength, coating type, opening size, thickness, and fiber material. Several different laboratory performance tests were conducted (Dynamic Complex Modulus, DCM, Overlay Test, OT, and Indirect Tensile Strength, ITS) and the fatigue and/or cracking performance was evaluated. Additionally, different approaches were adopted or developed for the modeling of geogrids in HMA using Finite Element Modeling (FEM). Finally, a Life-Cycle Cost …

Potential For On-Site, Prosecutorial Evidence From Drug Residues Collected On Plasmonic Paper: A Pilot Study For Sers-Psi-Ms, Daniel S. Burr

Theses and Dissertations

Given the potential impact of improvements to on-site drug testing, as well as recent, successful displays of paper spray ionization mass spectrometry (PSI-MS) in this regard, this thesis pilots the implementation of Raman spectroscopy as a compliment to MS for field-based confirmatory drug testing. Surface enhanced Raman scattering (SERS) is utilized for applications to trace detection. Two-tiered analysis of individual drug samples is enabled using triangularly-cut plasmonic papers, from which both SERS and PS-MS analysis may be performed. Several drug compounds, representative of traditional and emerging drug types, are examined by these techniques, both separately and as a fully integrated, …

Development Of A Simplified Performance-Based Procedure For Assessment Of Post-Liquefaction Settlement Using The Cone Penetration Test, Jingwen He

Theses and Dissertations

Earthquake-induced liquefaction can cause severe damage to infrastructure is a serious concern in civil engineering practice. Post-liquefaction settlement is one of the common effects of liquefaction. The ability to predict and quantify post-liquefaction free-field settlement is a crucial part of seismic design. Many approaches have been developed during the past 50 years to perform liquefaction hazard analysis. The performance-based earthquake engineering (PBEE) framework developed by the Pacific Earthquake Engineering Research (PEER) center is a probabilistic framework that can provide a more accurate and complete seismic hazard analysis than other traditional methods. However, the PBEE framework is not widely used in …

"Kompaktabiliteti Elektroenergjetik Kosovë-Shqipëri ", Adi Vokshi

Theses and Dissertations

Siç e dimë energjia elektrike është e nevojshme në të gjithë sektorët. Kjo shkakton kërkesë të madhe për energji elektrike edhe në Kosovë dhe Shqipëri.

Qëllimi i këtij punimi ështe që të analizohet prodhimi i energjisë elektrike në të dy vendet pasiqë ka mendime se një bashkim energjetik do të përmbushte këkesat për energji elektrike të të dy shteteve.

Por si është e mundur kjo?

Siç e dimë Kosova 97% të energjisë elektrike e prodhon nga termocentralet dhe ky është prodhim stabil 24/7. Ndërsa shqipëria 97% të energjisë e prodhon nga energjia hidrike, dhe kryesisht prodhimi me i madh arrihet …

Kontrollimi I Uljeve Dhe Plasaritjeve Në Traun Nga Betoni I Armuar Sipas Eurokodit 2 (Ec-2), Arxhent Jakupi

Theses and Dissertations

Situata e projektimit nga e cila mund t'a vërtetojmë se struktura jonë do të jetë e sigurtë nga veprimet e forcave është ajo e Gjendjes Kufitare të Shfrytëzimit. Në bazë të saj përcaktohet niveli i sigurisë së strukturës, nga e cila mund të mvaret edhe jetëgjatësia e saj. E gjitha kjo duhet bëhet që së paku struktura të qëndrojë e pamvarur duke mos pasur nevojë për intervenime pas një kohe jo të gjatë nga ndërtimi, të shfrytëzohet maksimalisht dhe duke mos shkaktuar pasoja në të ardhmen në njerëz apo qfarëdo qofshin ato.

Ky material mbulon gjendjet kufitare të përgjithëshme të …

Materialet Hidroizoluese, Arian Sadiku

Theses and Dissertations

Në këtë temë do të flasim për materialet hidroizoluese, në veçanti për llojet dhe karakteristikat e materialeve hidroizoluese me bazë polimere dhe të dhënat për materialet hidroizoluese. Janë përshkruar llojet dhe karakteristikat e materialeve si fizikia ndërtimore, rezistenca ndaj zjarrit, membrana hidroizoluese PVC, drenazhimi sipërfaqësor.

Një nga aplikimet më të rëndësishme në një ndërtim është hidroizolimi. Hidroizolimi përmirëson qëndrueshmërinë e shumë sipërfaqeve të ndryshme në ndërtim. Për më tepër, materialet hidroizoluese duhet të aplikohen në mënyrë që të sigurohet komoditeti i shtëpisë ose zyrës që do të përdoret pasi të përfundojë ndërtimi.

Hidroizolimi në ndërtesa është formimi i një pengese …

Astrocyte Sensitivity To Dopamine In Culture And Ex Vivo, Ashley L. Galloway

Theses and Dissertations

Dopamine is critical for processing of reward and etiology of drug addiction. Astrocytes throughout the brain express dopamine receptors, but consequences of astrocytic dopamine receptor signaling are not well established. This thesis illustrates effects of dopamine on cultured astrocytes and astrocytes in brain slices (ex vivo). In striatal cultures, extracellular dopamine triggered changes in astrocytic Ca²⁺ signaling and rapid concentration-dependent stellation of astrocytic processes that was not a result of dopamine oxidation, but instead relied on both cAMP-dependent and cAMP-independent dopamine receptor signaling. To isolate possible mechanisms underlying these structural and functional changes, whole-genome RNA sequencing was …

Interdependent Mechanisms Of Stress Susceptibility, Julie Elaine Finnell

Theses and Dissertations

Social stress is a significant risk factor for the emergence of psychiatric disorders including depression and anxiety. While there are a number of commercially available therapeutic options for the treatment of these disorders, these treatments require weeks of continuous use to produce behavioral efficacy. It has also been suggested that these traditional therapies are only marginally effective in producing complete remission, suggesting that our understanding as it pertains to the mechanisms underlying stressinduced behavioral dysfunction is still in its infancy. In the last few years, inflammation has become a major focus in the field of stress and depression as clinical …

Correlating Pressure, Fluidization Gas Velocities, Andsolids Mass Flowrates In A High-Pressurefluidized Bed Coal Feed System, Jacob Talailetalalelei Tuia

Theses and Dissertations

The goal of this thesis was to understand what parameters would be most impactful when delivering dry, pulverized coal in a dilute-phase, with a high-pressure feed-system to a pressurized oxy-combustion (POC) reactor. Many studies have conveyed materials in dense-phase plugs at high-pressure or in dilute-phase flows at atmospheric pressure. Very few studies have fluidized and conveyed materials in dilute-phase flows at high pressure, as we needed to. Additionally, studies which might have been applicable based upon system -pressure and -phase delivered findings that were empirically based and therefore not specifically applicable to non-similar systems. 220 different tests were ran using …

Joint Analysis Of And Applications For Devices With Expanding Motions, Kendall Hal Seymour

Theses and Dissertations

Origami has been extensively studied by engineers for its unique motions and ability to collapse to small volumes. Techniques have been studied for replicating origami-like folding motion in thick materials, but limited practical applications of these techniques have been demonstrated. Developable mechanisms are a new mechanism type that has a similar ability to collapse to a low profile. The cylindrical developable mechanism has the ability to emerge from and conform to a cylindrical surface. In this work, a few practical applications of devices with novel expanding motions are presented. The design and testing of an origami-inspired deployable ballistic barrier, which …

Implementation Of View Factor Model And Radiative Heat Transfer Model In Moose, Abdurrahman Ozturk

Theses and Dissertations

View factors are functions that represent the geometric relationship between surfaces. They are important parameters for radiative heat transfer calculations. View factor catalogues are available for simple geometries in the current literature. However, in the case of complicated geometry, analytical or numerical methods are needed to evaluate view factors. The Monte Carlo (MC) method is the most flexible one among numerical methods, which are used to calculate view factors, since it can be applied to any geometry.

When experimental studies are not affordable to conduct, modeling of engineering problems gains more importance. Idaho National Laboratory (INL)’s finite element framework Multiphysics …

Fractional Order And Virtual Variable Sampling Design Of Repetitive Control For Power Converters, Zhichao Liu

Theses and Dissertations

With the growth of electricity demand and renewable energy power source, power converter becomes a more and more significant component in electrical power systems. The requirement of the power converter controller is to produce an accurate and low-distorted voltage or current under different load conditions. Although the conventional controller can meet the requirement of some applications, it requires accurate knowledge of the system model and cannot provide a satisfactory result especially under nonlinear loads or sudden load change. Repetitive control (RC) presents an attractive solution to achieve excellent steady-state tracking error and low total harmonic distortion for periodic signals, and …

Dc Bus Stabilization And Dynamic Performance Improvement Of A Multi-Converter System, Silvia Arrua

Theses and Dissertations

Evolution of semiconductor devices is allowing to implement power electronics technology in a variety of applications, moving traditional AC systems to more efficient and reliable DC systems. Some examples are shipboard power distribution systems, DC microgrids, electric vehicles and more electric aircrafts. Even though these types of systems offer significant advantages that make them attractive in different areas, the interconnection of feedback-controlled power converters leads to emergent dynamic behavior that a system designer must take into account to ensure proper operation of the system. Additionally, system reconfiguration is very likely to happen in applications such as a shipboard power distribution, …

The Contribution Of Adipose Tissue From Ovariectomized Mice To Colon Cancer, Meredith Smith Carson

Theses and Dissertations

Obesity is considered a major public health concern worldwide due to the increased incidences of metabolic dysfunction and cancer risk. The obese state is, in part, attributable to the overconsumption of calorie-dense foods commonly seen in a standard Western diet, which aids in the progression of chronic, lowgrade inflammation. The role of estrogen varies depending on menopausal status, where estrogen deficiency coupled with increased visceral fat associated with post-menopause leads to increased secretions of pro-inflammatory adipokines and cytokines. However, the presence of estrogen in a premenopausal state has been shown to attenuate the pro-inflammatory response, which has been demonstrated when …

Developing An Automation Locus Of Control Scale, Maarten Nelson Devon Edwards

Theses and Dissertations

The industrial and domestic proliferation of automation is such that it has become a core component of the human experience. Both automation design paradigms and human performance must be scrutinized in order to ensure the safety, security, effectiveness and efficiency of man-machine systems across a multitude of domains (Fitts, 1951; Parasuraman, Sheridan, & Wickens, 2000; Rasmussen, 1983). Therefore, the purpose of this study was to develop and validate a measure for the evaluation of control perceptions in the context of human-automation interactions. The scale was developed using a deductive approach to measure development adapting from Rotter (1966) and Levenson (1973) …

Gene Expression Studies For Analyzing Effects Of Space Radiation In Tissues, Amatulshakoor Mohammed Farooqui

Theses and Dissertations

Human exploration beyond the earth's orbit poses many risks for the crew on these missions. One of the major health risks is exposure to space radiation environment beyond the earth’s magnetic field. The space environment exposes astronauts to high levels of ionizing radiation such as galactic cosmic rays. The radiations can have acute and delayed effects on the human body. The primary response to tissue injury is increased oxidative stress and inflammation. The overall objective of this study was to analyze the effects of ionizing radiation in heart tissue by quantifying its impact on the expression of genes that correlate …

Analysis Of Pile Driving Monitoring Equipment, Robert Joseph Rogulski Iii

Theses and Dissertations

Rebound is a problem affecting pile driving in Florida. Significant rebound can require excessive blows for a pile to reach bearing capacity and may damage the pile. In order to study rebound, precise instrumentation is required. For that reason, the objective of this thesis is to evaluate the Inopile’s Pile Driving Monitor (PDM) as a tool for measuring the rebound of large diameter pre-stressed concrete piles driven with open ended diesel hammers. Six sites from Florida were selected for testing. Five of the sites had pile driving and two of them had standard penetration testing (which was used as an …

Surface Phonon Polariton-Enhanced Ring Resonator And E-Plane Hybrid Ring Coupler, Cláudio Augusto Barreto Saunders Filho

Theses and Dissertations

Surface polaritons are known for providing the ability to confine light beyond the Abbe’s limit of diffraction. While metals efficiently support surface plasmon polaritons in the visible-UV spectrum, some semiconductors can support surface phonon polaritons in the infrared. Ring resonators are devices with high integration level with optical interconnects and with applications including filters, directional couplers, modulators and interferometers. Loss associated to ring curvature yields ring radius on the order of tens of free-space wavelengths. SPhP-enhanced micro-ring resonator was proposed and it was shown that ring dimensions are reduced. Advances in nanofabrication processes allow the design of optical interconnects using …

Advancing Numerical Calculation Of Mixed Sized Sediment Transport And Morphology Change, Irene Margaret Watts

Theses and Dissertations

Numerical modeling of sediment transport and morphologic change has become a powerful tool for studying and working in the coastal zone. Numerical calculation can assist in a broad range of projects from regional sediment management to beach nourishment as well as evaluating environmental aspects of dredging and placement and implications to water quality and turbidity. Success in application of these tools is partially dependent on the quality of characterization of the sediments in the field. These parameters could include grain size, mineralogical composition, specific gravity and fall velocity. Sediment transport formulations are sensitive to the spatial representation of the sediments …

A Coastal Estuarine Ensemble Forecasting System, Peyman Taeb

Theses and Dissertations

This research has been conducted in an effort to reduce the computational costs associated with high-resolution coastal estuarine modeling in ADCIRC. It was proposed that model scalability will be significantly enhanced if the conventional single-domain technique is replaced by a nesting method. Preliminary testing indicated the potential for 50% to more than 80% simulation runtime reduction (depending on the study site) by implementing a nesting technique. Once the concept was proved, the development of an operational, ensemble-based forecasting system, exclusively for the east coast of Central Florida and the IRL system, was implemented. The system, referred to as Ensemble Multistage, …

Developing An Interview Protocol For An Engineering Design Capstone Course To Measure Student Motivation And Engineering Identity, Mckenzie Clark

Theses and Dissertations

This thesis examines the process of developing an effective in-depth interview protocol to measure student motivation and engineering identity. Several methods were employed during the creation, refining, and analysis portions of this study to ensure reliability and validity of the qualitative research instrument. In a multifaceted course such as senior capstone design, it is integral to ensure students are receiving a value adding experience. In most universities across the United States, senior capstone design is a multiple semester sequence where design is heavily emphasized and students are encouraged to test their skills, both technical and nontechnical, by solving and implementing …

Modeling To Predict The Salt Transport Between A Scale Model Estuary And The Unconfined Aquifer With Groundwater Flow, Abeer Ibraheem Khazaly

Theses and Dissertations

In many field studies, variation in fluid density may have important effects on controlling groundwater flow and solute transport processes. These studies include: Indian River Lagoon (IRL), a coastal estuary, located on the east coast of Florida, saline disposal basins, radioactive waste disposal and contaminant spills. In the environment, where the fresh groundwater region is in direct contact with the saline seawater region in coastal aquifers, dynamic equilibrium normally exists between these two regions, but there are numerous human and environmental factors that can adversely impact the equilibrium and lead to severe saltwater contamination of the freshwater region. Intrusion of …

Development Of Prognostics Techniques For Surface Defect Growth In Railroad Bearing Rolling Elements, Nancy De Los Santos

Theses and Dissertations

One of the major causes of failure in railroad bearings used in freight service is rolling contact fatigue (RCF). RCF is due to subsurface inclusions which are a result from impurities in the steel that is used to fabricate the bearings. Once the bearings initiate subsurface fatigue cracks, they will then propagate upward and initiate spalling of the rolling surfaces. These spalls will begin small and continuously propagate with operation as this induces additional crack forming and spalling. Studies have indicated that bearing temperature is not a good indicator of spall initiation. In many cases, the temperature of the bearing …